The evidence supporting sensible sun exposure is strong and clear, while there’s little evidence that sunscreen use protects against skin cancer, or that vitamin D supplements are bioequivalent to sunshine

By Dr. Mercola

In July 2014, the interim U.S. Surgeon General Dr. Boris Lushniak, who is also a dermatologist, issued a "Call to Action to Prevent Skin Cancer,"1,2 in which he declared UV radiation harmful and said sun exposure should be avoided altogether.

The American Academy of Dermatology and The Skin Cancer Foundation also advocate avoiding all sun exposure — regardless of the color of your skin — saying vitamin D supplementation can address any deficiencies.

This is an irrational and shortsighted position that lacks any credibility. The scientific evidence, now running in excess of 34,000 studies, detail that UV exposure is essential, both for vitamin D production and other benefits unrelated to vitamin D.

The color of your skin is a significant factor to determine appropriate exposure times and any advice that does not take this into consideration is illogical. We are not nocturnal beings, avoiding the sun entirely is horrible advice that should not be followed.

Dermatologists' Position on Sun Exposure Riddled With Fatal Flaws

Let's remember that, because of their irrational concern, they were able to convince public health officials and media to convince people to use sunscreens.

What happened as a result of the public adopting this proactive "preventive" approach? Skin cancers actually increased.

Why? Because the dermatologists did not do their homework. Most sunscreens blocked UVB, which causes vitamin D levels to increase and lower cancer rates, but they let UVA, which can cause skin cancer when excessively exposed, to shine right through like a hot knife through butter.

What's worse, they never admitted to their egregious mistake. Ironically, the only location dermatologists approve of UV light treatment is in their office under costly supervision.

Avoiding Sun Exposure Radically Worsens Disease Rates

UVB exposure is essential for optimal health, and any risks of exposure are related to over exposure and burning. Research shows vitamin D is involved in the biochemical regulation of nearly every cell in your body, including your immune system.

Vitamin D deficiency can deteriorate your health in a number of different ways, as your cells need the active form of vitamin D to optimally regulate genetic expression.

As noted by William Grant, Ph.D., head of the Sunlight, Nutrition and Health Research Center (SUNARC), staying indoors to avoid sun exposure is "not particularly good advice," adding that:3

"There are several papers indicating that occupational exposure to sunlight reduces the risk of melanoma. It is having fair skin, a high-fat, low fruit and vegetable diet, sunburning, etc., that are more linked to melanoma than total UV exposure."

Vitamin D Is Crucial for Pregnant Women

Vitamin D is particularly important for pregnant women, as deficiency affects both the mother and her child in the short and long term, including raising the child's long-term risk for diabetes, allergic rhinitis,4 arthritis, stroke, and cardiovascular disease.

Recent research shows that raising maternal vitamin D levels helps children born in winter months develop stronger, healthier bones.5 Lead researcher Professor Nicholas Harvey, Ph.D., of the University of Southampton, also notes that sun exposure is the most important source of vitamin D.

Health initiatives such as GrassrootsHealth D*Action study,6 and the Protect Our Children NOW! campaign are both based on these fundamental and scientifically proven facts.

Dermatologists Ignore Skin Color

The fact that the American Academy of Dermatology issues the same recommendations for everyone, without regard for skin type, is telling. Despite overwhelming evidence to the contrary, they view sun exposure as nothing but a dangerous cancer risk to be avoided at all costs.

This is a really nonsensical, and most definitively nonscientific, stance. According to their advice, even if you have the darkest skin, you should always seek shade and wear protective clothing and/or sunscreen when outdoors.

The notion that supplements are bioequivalent to sunshine is lacking. While I recommend supplements if UVB exposure is not available, to suggest that vitamin D can replace all the benefits of sun exposure is ridiculous.

In fact, each of us responds quite differently to vitamin D supplementation - there is a 6 to 10 times difference in dosage response between individuals. If you are supplementing with vitamin D, you should have your levels checked twice per year to ensure you stay above 40ng/ml.

Because of this, vitamin D experts such as Grant and Dr. Michael F. Holick note that sensible sun exposure is far preferable to vitamin D supplementation.

Oversimplifying the Issue Is Not a Good Public Health Policy

The Skin Cancer Foundation echoes the American Academy of Dermatology's recommendations.

When questioned about this philosophy and asked why the recommendations fail to take into account skin type and color, Dr. Henry Lim, who sits on The Skin Cancer Foundation's photobiology committee, replied that such information is irrelevant because vitamin D supplements can address deficiency.

"We want to make it simple as a public health message — as to what the public should reasonably be able to absorb and understand. To fine tune it is just too complicated we feel."

But by oversimplifying the matter, dermatologists place a great number of people at grave risk for vitamin D deficiency, which may not be identified until health problems have already set in. Moreover, the advice to use sunscreen is also on shaky scientific ground.

According to an analysis by epidemiologist Marianne Berwick, Ph.D., there's very little evidence to suggest that sunscreen use will prevent skin cancer.

After analyzing a dozen studies on basal cell carcinoma, which is typically non-lethal, and the more deadly melanoma, Berwick found that people who use sunscreen tend to be more likely to develop both of these conditions.

Only 2 of 10 melanoma studies found that sunscreen was protective against this condition; three found no association either way. None found sunscreen use protected against basal cell carcinoma.8

Darker-skinned people not only need more sun exposure to produce sufficient amounts of vitamin D, they're also more protected from skin cancer due to their skin pigmentation. Yet this important reality is simply ignored by dermatologists, resulting in most African Americans being at a radically increased risk of cancers and heart disease from vitamin D deficiency.

"How the sun affects you depends on your complexion, the shade of which is determined by melanin ... The anti-oxidizing molecule is so versatile at protecting and repairing DNA from UV solar radiation that creatures from humans to fungi deploy it ... [T]he melanin sits atop cellular DNA like tiny umbrellas pointed ... out to shield from incoming rays ...

[T]he same ultraviolet wavelengths in the 290 to 400 nanometers range that trigger melanin production also spark vitamin D creation. You cannot make one without the other.

Humans evolved to produce two kinds of melanin ... The MC1R gene determines the type of melanin the body produces. In the mid-zone such as the Mediterranean region, people ... produce eumelanin, the pigment responsible for brown or black hair and for dark skin that tans easily ...

[I]n far northern Europe, humans paled, adapting to lower light ... with a different type of melanin, called pheomelanin, associated with fair skin and blonde and red hair with minimal protective value, but allowing more UV to penetrate to make vitamin D. "

Sun Avoidance Raises Risk of Internal Cancers

Dermatology is focused on one primary outcome — avoiding skin damage and skin cancer. But by focusing on just one side of the UV exposure issue, they're actually promoting a lifestyle that may raise your risk of other lethal cancers and chronic diseases. Not only have higher vitamin D levels been shown to offer significant protection against a number of internal cancers, there's also evidence showing higher levels offer protection against melanoma.

In fact, higher rates of melanoma are found among those who have low vitamin D levels; among indoor occupations; and in areas of the body that rarely or never see the light of day. In short, the vitamin D your body produces in response to UVB radiation is protective against skin cancer. As noted in The Lancet:10

"Paradoxically, outdoor workers have a decreased risk of melanoma compared with indoor workers, suggesting that chronic sunlight exposure can have a protective effect."

Even more importantly, vitamin D has been shown to significantly reduce internal cancers, along with chronic diseases such as heart disease, which kill far more people than melanoma does. Breast11 and prostate12,13 cancers are just two examples where low vitamin D renders you more vulnerable to more aggressive forms of the disease. Recent research14 has also found that low vitamin D levels are associated with more severe peripheral neuropathy in cancer patients.

"The researchers linked vitamin D levels to the ID1 gene, which at high levels of expression is associated with breast cancer tumor growth. Past studies have shown that vitamin D is linked to inhibiting the expression of this gene, and that low vitamin D levels have been associated with more aggressive tumors. "

Public Health Messages Should Be Based on All-Cause Mortality Reduction

According to a scientific review16 by Dr. Richard Weller, a dermatologist, sun exposure also has cardiovascular benefits independent of vitamin D. One of the key messages presented in his paper states that: "All-cause mortality should be the primary determinant of public health messages. Sunlight is a risk factor for skin cancer, but sun avoidance may carry more of a cost than benefit for overall good health."

Another study17 published in the journal Public Health Nutrition in 2012 concluded that: "The overall health benefit of an improved vitamin D status may be more important than the possibly increased CMM (cutaneous malignant melanoma) risk resulting from carefully increasing UV exposure. Important scientific facts behind this judgment are given."

In short, if you're concerned about mortality, and not just mortality from one disease, the scales are decidedly tipped toward sun exposure being of tremendous benefit — despite a minor risk of melanoma, should you accidentally end up getting burned one or more times in your life. Unfortunately, the field of dermatology refuses to take the entire picture into account when making its recommendations about UV exposure.

UV Light Is Essential for Human Health

We are not nocturnal beings, and while high intermittent and/or overexposure to UV light can cause potentially serious harm, it's a manageable risk provided you use common sense and pay careful attention to some basic elements. The advice to completely avoid UV light is quite dangerous, and one that extends far beyond just vitamin D deficiency, as sunlight has health benefits that go beyond vitamin D production.

To mitigate the risks of UV exposure while maximizing the benefits, here are some factors to consider:

Our skin pigmentations are linked to ancestral latitudinal proximities that optimized our ancestors' skin for sun exposure. The further from the equator our ancestors lived, the lighter their skin, allowing them to biologically maximize the limited availability of the sun, and UV light specifically. Remember: Your body produces vitamin D through exposure to UVB light. For those living in northern latitudes, this may only be an option for a few short months each year.

If you accept the essential nature of UV light, then you can conclude that safe exposure to sunshine is possible by understanding your skin type, the UV strength at the time of exposure, and your duration of exposure. My advice has been clear: Always avoid sunburn.

Pay close attention to your vitamin D levels. Ideally, get your vitamin D tested during the peak of summer and at the end of winter to help guide your UV exposure and vitamin D supplementation.

UVB exposure on bare skin is required for your body to produce vitamin D. The more skin that is exposed when UVB is available, the less time you need. Since few foods contain any significant amount of vitamin D, and your body certainly was not designed to get its vitamin D from supplements, which are a modern invention, the only rational conclusion is that sun exposure is the ideal way to raise your vitamin D level.

UV light has benefits beyond vitamin D. For more information, see the TED Talk above, or read through "Sunlight Has Cardiovascular Benefits Independently of Vitamin D," 19,20 produced by Richard B. Weller Medical Research Council Centre for Inflammation Research, University of Edinburgh.